Available methods for treatment of hazardous wastes are limited. Conventional methods for disposal of hazardous wastes, such as incineration, can also contaminate the environment. For example, incomplete combustion of hazardous wastes typically causes release of pollutants to the atmosphere in the form of gases and dust. Many types of hazardous wastes are generated every year. The wastes include organic materials, such as pesticides, polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), paints and solvents. Also, other wastes include inorganic material, such as the oxides of iron, zinc, aluminum, copper and magnesium and the salts of ferric chloride, ferrous chloride, aluminum chloride, etc.
Disposal of hazardous wastes in landfills and by incineration has become an increasingly difficult problem because of diminishing availability of disposal space, strengthened governmental regulations, and the growing public awareness of the impact of hazardous substance contamination of the environment. Release of hazardous organic wastes to the environment can contaminate air and water supplies, thereby diminishing the quality of life in the affected populations.
One alternative treatment of hazardous wastes includes introduction of the wastes into a molten bath, such as a molten metal bath. Typically, the wastes are directed onto the top of a molten bath contained within a suitable reactor. However, wastes often do not mix well with the bath and are consequently discharged from the reactor before decomposition is complete.
In another method, solid wastes are suspended in an inert gas and injected into a molten bath. However, containment and transfer of solids suspended in an inert gas can be difficult. For example, in Q-BOP facilities, powder injection equipment is confined to an enclosed area in an effort to contain spillage. Plugging, valve and instrument damage, transfer of solids to an injection unit and accidental release of solids can make the operation problematic.
Therefore, a need exists for a method and apparatus for injection of solids into molten baths which overcome or minimize the above-mentioned problems.